var DS_x,DS_y;

function dateSelector(datetime)  //构造dateSelector对象，用来实现一个日历形式的日期输入框。
{
        if (datetime) 
        {
                var splits = datetime.split("-");
                this.year = parseInt(splits[0]);
                this.month = parseInt(splits[1]);
                this.date = parseInt(splits[2]);
        }
        else
        {
                var myDate=new Date();
                this.year=myDate.getFullYear();  //定义year属性，年份，默认值为当前系统年份。
                this.month=myDate.getMonth()+1; 
                this.date=myDate.getDate();
        }
        this.inputID='';  //定义input ID属性，即输入框的ID，默认值为空。
        this.inputName='';  //定义inputName属性，即输入框的name，默认值为空。注意：在同一页中出现多个日期输入框，不能有重复的name！
        this.display=display;  //定义display方法，用来显示日期输入框。
}

function display()  //定义dateSelector的display方法，它将实现一个日历形式的日期选择框。
{
        var week=new Array('日','一','二','三','四','五','六');

        var month = this.month >= 10 ? this.month : "0"+this.month ;  //定义month属性，月份，默认值为当前系统月份。
        var date = this.date >= 10 ? this.date : "0"+this.date ;   //定义date属性，日，默认值为当前系统的日。
        document.write("<style type=text/css>");
        document.write("  .ds_font td  { font: normal 12px 宋体; color: #000000; }");
        document.write("  #spa  { font: normal 12px 宋体; color: #000000; }");
        document.write("  .ds_border  { border: 1px solid #000000; cursor: hand; background-color: #DDDDDD }");
        document.write("  .ds_border2  { border: 1px solid #000000; cursor: hand; background-color: #DDDDDD }");
        document.write("  #cal_tb td { border-width:0 0 0 0; padding:0 0 0 0 }");
        document.write("</style>");

        document.write("<input style='text-align:center' id='DS_"+this.inputID+"' name='"+this.inputName+"' value='"+this.year+"-"+month+"-"+date+"' title=双击可进行编缉 ondblclick='this.readOnly=false;this.focus()' onblur=\"this.readOnly=true;onblur=document.all('DS_"+this.inputID+"').nextSibling.nextSibling.style.display='none'\" readonly>");
        document.write("<button style='width:60px;height:18px;font-size:12px;margin:1px;border:1px solid #A4B3C8;background-color:#DFE7EF;' type=button onclick=this.nextSibling.style.display='block' onfocus=this.blur()>选择日期</button>"); // 

        document.write("<div style='position:absolute;display:none;text-align:center;width:0px;height:0px;overflow:visible' onselectstart='return false;'>");
        document.write("  <div style='position:absolute;left:-60px;top:24px;width:142px;height:165px;background-color:#F6F6F6;border:1px solid #245B7D;' class=ds_font>");
        document.write("    <table id='cal_tb' cellpadding=0 cellspacing=1 width=140 height=20 bgcolor=#CEDAE7 onmousedown='DS_x=event.x-parentNode.style.pixelLeft;DS_y=event.y-parentNode.style.pixelTop;setCapture();' onmouseup='releaseCapture();' onmousemove='dsMove(this.parentNode)'style='cursor:move;'>");
        document.write("      <tr align=center>");
        document.write("        <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=subYear(this) title='减小年份'><<</td>");
        document.write("        <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=subMonth(this) title='减小月份'><</td>");
        document.write("        <td width=52%><b>"+this.year+"</b><b>年</b><b>"+this.month+"</b><b>月</b></td>");
        document.write("        <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=addMonth(this) title='增加月份'>></td>");
        document.write("        <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=addYear(this) title='增加年份'>>></td>");
        document.write("      </tr>");
        document.write("    </table>");

        document.write("    <table id='cal_tb' cellpadding=0 cellspacing=0 width=140 height=20 onmousedown='DS_x=event.x-parentNode.style.pixelLeft;DS_y=event.y-parentNode.style.pixelTop;setCapture();' onmouseup='releaseCapture();' onmousemove='dsMove(this.parentNode)' style='cursor:move;'>");
        document.write("      <tr align=center>");
        for(i=0;i<7;i++)
                document.write("      <td>"+week[i]+"</td>");
        document.write("      </tr>");
        document.write("    </table>");

        document.write("    <table id='cal_tb' cellpadding=0 cellspacing=2 width=140 bgcolor=#EEEEEE>");
        for(i=0;i<6;i++)
        {
                document.write("    <tr align=center>");
                for(j=0;j<7;j++)
                        document.write("    <td width=10% height=16 onmouseover=if(this.innerText!=''&&this.className!='ds_border2')this.className='ds_border' onmouseout=if(this.className!='ds_border2')this.className='' onclick=getvalue(this,document.all('DS_"+this.inputID+"'))></td>");
                document.write("    </tr>");
        }
        document.write("    </table>");

        document.write("    <span id='spa' style=cursor:hand onclick=this.parentNode.parentNode.style.display='none'>【关闭】</span>");
        document.write("  </div>");
        document.write("</div>");

        dateShow(document.all("DS_"+this.inputID).nextSibling.nextSibling.childNodes[0].childNodes[2],this.year,this.month);
}

function subYear(obj)  //减小年份
{
        var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
        myObj[0].innerHTML=eval(myObj[0].innerHTML)-1;
        dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}

function addYear(obj)  //增加年份
{
        var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
        myObj[0].innerHTML=eval(myObj[0].innerHTML)+1;
        dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}

function subMonth(obj)  //减小月份
{
        var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
        var month=eval(myObj[2].innerHTML)-1;
        if(month==0)
        {
                month=12;
                subYear(obj);
        }
        myObj[2].innerHTML=month;
        dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}

function addMonth(obj)  //增加月份
{
        var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
        var month=eval(myObj[2].innerHTML)+1;
        if(month==13)
        {
                month=1;
                addYear(obj);
        }
        myObj[2].innerHTML=month;
        dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}

function dateShow(obj,year,month)  //显示各月份的日
{
        var myDate=new Date(year,month-1,1);
        var today=new Date();
        var day=myDate.getDay();
        var selectDate=obj.parentNode.parentNode.previousSibling.previousSibling.value.split('-');
        var length;
        switch(parseInt(month))
        {
                case 1:
                case 3:
                case 5:
                case 7:
                case 8:
                case 10:
                case 12:
                        length=31;
                        break;
                case 4:
                case 6:
                case 9:
                case 11:
                        length=30;
                        break;
                case 2:
                        if((year%4==0)&&(year%100!=0)||(year%400==0))
                                length=29;
                        else
                                length=28;
        }
        for(i=0;i<obj.cells.length;i++)
        {
                obj.cells[i].innerHTML='';
                obj.cells[i].style.color='';
                obj.cells[i].className='';
        }
        for(i=0;i<length;i++)
        {
                obj.cells[i+day].innerHTML=(i+1);
                if(year==today.getFullYear()&&(month-1)==today.getMonth()&&(i+1)==today.getDate())
                        obj.cells[i+day].style.color='red';
                if(year==eval(selectDate[0])&&month==eval(selectDate[1])&&(i+1)==eval(selectDate[2]))
                        obj.cells[i+day].className='ds_border2';
        }
}

function getvalue(obj,inputObj)  //把选择的日期传给输入框
{
        var myObj=inputObj.nextSibling.nextSibling.childNodes[0].childNodes[0].cells[2].childNodes;
        if(obj.innerHTML)
        {
                var month = myObj[2].innerHTML >= 10 ? myObj[2].innerHTML : "0"+myObj[2].innerHTML ;
                var date = obj.innerHTML >= 10 ? obj.innerHTML : "0"+obj.innerHTML ;
                inputObj.value=myObj[0].innerHTML+"-"+month+"-"+date;
        }
        inputObj.nextSibling.nextSibling.style.display='none';
        for(i=0;i<obj.parentNode.parentNode.parentNode.cells.length;i++)
                obj.parentNode.parentNode.parentNode.cells[i].className='';
        obj.className='ds_border2'
}

function dsMove(obj)  //实现层的拖移
{
        if(event.button==1)
        {
                var X=obj.clientLeft;
                var Y=obj.clientTop;
                obj.style.pixelLeft=X+(event.x-DS_x);
                obj.style.pixelTop=Y+(event.y-DS_y);
        }
}
